Re: Trigger

Craig May wrote:
>
> Could someone send me a quick example of a trigger.

Hope this helps.

Chris Ryan

<<< Clip below and execute to create example >>>
--
-- FUNCTION: trigger_last_updated
--
-- DESCRIPTION:
-- This is a function called by the table triggers to update the
last_updated
-- field on insert and updates.
--
create function trigger_last_updated()
returns opaque
as 'begin
new.last_updated := now();
return new;
end;'
language 'plpgsql';

--
-- TABLE: test_tbl
--
-- DESCRIPTION:
-- A simple table to test my trigger
--
create table test_tbl (
some_field varchar(10),
last_updated timestamp not null default now()
);

--
-- TRIGGER: trigger_insert_update_test_tbl
--
-- DESCRIPTION:
-- This is the trigger called on insert and updates of all the table
that
-- has the last_updated field. It will use the function
trigger_last_updated
-- The cool thing here is the function doesn't make specific reference
to the
-- table so you could create a different trigger for each table with the
field
-- last_updated and use the same function.
--
create trigger trigger_insert_update_test_tbl
before insert or update on test_tbl
for each row execute procedure trigger_last_updated();